<?php

function getBrowser() {
    $u_agent = $_SERVER['HTTP_USER_AGENT'];
    $bname = 'Unknown';
    $platform = 'Unknown';
    $version = "";

    //First get the platform?
    if (preg_match('/linux/i', $u_agent)) {
        $platform = 'linux';
    } elseif (preg_match('/macintosh|mac os x/i', $u_agent)) {
        $platform = 'mac';
    } elseif (preg_match('/windows|win32/i', $u_agent)) {
        $platform = 'windows';
    }

    // Next get the name of the useragent yes seperately and for good reason
    $ub = "";
    if (preg_match('/MSIE/i', $u_agent) && !preg_match('/Opera/i', $u_agent)) {
        $bname = 'Internet Explorer';
        $ub = "MSIE";
    } elseif (preg_match('/Firefox/i', $u_agent)) {
        $bname = 'Mozilla Firefox';
        $ub = "Firefox";
    } elseif (preg_match('/Chrome/i', $u_agent)) {
        $bname = 'Google Chrome';
        $ub = "Chrome";
    } elseif (preg_match('/Safari/i', $u_agent)) {
        $bname = 'Apple Safari';
        $ub = "Safari";
    } elseif (preg_match('/Opera/i', $u_agent)) {
        $bname = 'Opera';
        $ub = "Opera";
    } elseif (preg_match('/Netscape/i', $u_agent)) {
        $bname = 'Netscape';
        $ub = "Netscape";
    }

    // finally get the correct version number
    $known = array('Version', $ub, 'other');
    $pattern = '#(?<browser>' . join('|', $known) .
            ')[/ ]+(?<version>[0-9.|a-zA-Z.]*)#';
    if (!preg_match_all($pattern, $u_agent, $matches)) {
        // we have no matching number just continue
    }

    // see how many we have
    $i = count($matches['browser']);
    if ($i != 1) {
        //we will have two since we are not using 'other' argument yet
        //see if version is before or after the name
        if (strripos($u_agent, "Version") < strripos($u_agent, $ub)) {
            $version = $matches['version'][0];
        } else {
            $version = $matches['version'][1];
        }
    } else {
        $version = $matches['version'][0];
    }

    // check if we have a number
    if ($version == null || $version == "") {
        $version = "?";
    }

    return array(
        'userAgent' => $u_agent,
        'name' => $bname,
        'version' => $version,
        'platform' => $platform,
        'nombre' => $ub,
        'pattern' => $pattern
    );
}

function validarNavegador() {
    $navegador = getBrowser();
    $version = explode(".", $navegador['version']);
    $v = (double) $version[0] . '.' . $version[1];
    if ($navegador['nombre'] == 'MSIE' && $v < 9
            || $navegador['nombre'] == 'Firefox' && $v == 4
            || $navegador['nombre'] == 'Safari' && $v <= 4
            || $navegador['nombre'] == 'Opera' && $v <= 10
            || $navegador['nombre'] == 'Chrome' && $v <= 8) {
        return false;
    } else {
        return true;
    }
}

// now try it
//$ua = getBrowser();
//$yourbrowser = $ua['nombre'] . "Your browser: " . $ua['name'] . " " . $ua['version'] . " on " . $ua['platform'] . " reports: <br >" . $ua['userAgent'];
//print_r($yourbrowser);
//
?>